Bergdahl, a US airborne infantryman, was captured by the Afghan Taliban in Paktika province on Jun 30.
The insurgents also released a video of Bergdahl a few weeks after he was captured.
Taliban's decision to release the video on Christmas Day was an affront to the soldier's family, NATO commanders said.
NATO commanders also said they will continue searching for the captured soldier.
They have dismissed Taliban demands to free military prisoners in exchange for Private Bergdahl's release.
The family has issued a statement pleading with his captors to release their son and urging him to stay strong.